6. The science of smiles. Interestingly, mimicry helps people figure out which smiles are real, and which are fake. A tip: If you want to know whether someone is genuinely smiling, check the movement of their orbicularis oculi. If it pulls downward when they flash their pearly whites, you will know that the smile is genuine. Note that the movement of the orbicularis oculi in that situation is involuntary; as David Brooks notes, the muscle cannot be consciously controlled.